A buck converter, also called buck regulator or DC-DC step-down switching regulator, is a type of DC-DC converter that provides an output regulated voltage that is lower than its input voltage.
ST's monolithic step-down (buck) converter ICs offer input-voltage capability up to 61 V and deliver output currents up to 4 A with high switching frequency.
These buck regulators embed a full set of protection functions (overcurrent, overvoltage, and over-temperature) to increase the mean time between failures (MTBF) and reduce the number of external components required, thus lowering BOM costs.

Monolithic buck converter ICs (buck regulator) for any application requirement
- ST offers high performance and high flexibility AEC-Q100 compliant buck converters for automotive applications.
- See all Automotive buck converters
- High reliability and excellent robustness buck converters, for industrial and any application requiring a wide range of input output voltages.
- See all Industrial buck converters
Product types: how to choose the right buck converter
Learn about ST broad selection of buck converters, designed to meet a wide range of requirements.



Low-consumption buck converters feature ultra-low quiescent current and high efficiency at light load to meet these application requirements.

However, they also introduce switching noise that could represent a big obstacle to comply with EMI standards and disturb noise-sensitive applications.
Low-noise buck converters help designers meet these challenges.


A short on-time ensures a large input-to-output conversion ratio while maintaining a high switching frequency.
Benefits
- High-voltage technology together with high reliability, robustness, and compactness
- High efficiency at any load and a high level of performance for consumer and computer products
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About buck converters
How does a buck converter work?
A buck converter usually uses two switches and an inductor to make a voltage controlled current source that interacts with the parallel combination of output capacitor and load, to generate the desired output voltage (VOUT < VIN).
Where and why is a buck converter used?
A buck converter is used to step down the voltage of a given input to achieve the required output voltage. Buck converters can be used in many applications, including smartphones, tablets, battery-powered equipment, industrial power systems and point-of-load supplies.
What are the advantages of a buck converter?
Buck converters offer a more efficient solution with fewer, smaller external components. They can step-down voltages using a minimal number of components. In the same time, they offer a lower operating duty cycle and higher efficiency across a wide range of input and output voltages.
- L5983 1.5 A step-down switching regulator
- L5985 2 A step-down switching regulator
- A7987 61 V 3A asynchronous step-down switching regulator with adjustable current limitation for automotive
- ST1PS03 400 mA nano-quiescent synchronous step-down converter with digital voltage selection, Power Good and independent Load Switch
- ST1PS01 400 mA nano-quiescent synchronous step-down converter with digital voltage selection and Power Good
- L5980 0.7 A step-down switching regulator
- ST1S09 2 A, 1.5 MHz PWM step-down switching regulator with synchronous rectification
- L5981 1 A step-down switching regulator
- A5972D Up to 1.5 A step-down switching regulator for automotive applications
- A5973AD Up to 1.5 A step-down switching regulator for automotive applications
- L7983 60 V 300 mA synchronous step-down switching regulator with 10 µA quiescent current
- A5970AD Up to 1 A step down switching regulator for automotive applications
- A5970D Up to 1 A step-down switching regulator for automotive applications
- L6983 38 V, 3 A synchronous step-down converter with 17 µA quiescent current
- A5973D Up to 2 A step down switching regulator for automotive applications
- A6902D Up to 1 A step down switching regulator with adjustable current limit for automotive applications
- L5973D Up to 2 A step down switching regulator
- AST1S31HF Up to 4 V, 3 A step-down 2.3 MHz switching regulator for automotive applications
- ST1S14 Up to 3 A step-down switching regulator
- L5972D 2A switch step down switching regulator
- L7981 3 A step-down switching regulator
- ST1S30 3 A, 1.5 MHz PWM step-down switching regulator with synchronous rectification
- L7980 2 A step-down switching regulator
- ST1S31 3 A DC step-down switching regulator
- L6984 36 V, 400 mA synchronous step-down switching regulator
- L6986 38 V, 2 A synchronous step-down switching regulator with 30 µA quiescent current
- PM8903A 3 A step-down monolithic switching regulator
- L4964 High current switching regulator
- L6986I 38 V, 5W synchronous iso-buck converter
- A6986I Automotive 38 V, 5W synchronous iso-buck converter
- L5988D 4 A continuous (more than 5 A pulsed) step-down switching regulator with synchronous rectification
- A5974D Up to 2.5 A step down switching regulator for automotive applications
- L6986H 38 V, 2 A synchronous step-down switching regulator with 30 µA quiescent current
- L296 HIGH CURRENT SWITCHING REGULATORS
- L5970D Up to 1 A step down switching regulator
- AST1S31 Up to 4 V, 3 A step-down 1.5 MHz switching regulator for automotive applications
- L4978 2A Step down switching regulator
- L7987 61 V 3 A asynchronous step-down switching regulator with adjustable current limitation
- ST1S50 4 A Monolithic synchronous step-down converter with high efficiency at light load
- STPD01 Programmable Buck Converter for USB Power Delivery
- L5973AD 2 A switch step down switching regulator
- A6986F Automotive 38 V, 1.5 A synchronous step-down switching regulator with 30 µA quiescent current
- L6986F 38 V, 1.5 A synchronous step-down switching regulator with 30 µA quiescent current
- ST1S15 500 mA, 6 MHz synchronous step-down converter
- ST1PS02 400 mA nano-quiescent synchronous step-down converter with digital voltage selection, Power Good and AUX switch
- L4976 1 A step down switching regulator
- A5975D Up to 3 A step down switching regulator for automotive applications
- A6984 36 V 400 mA synchronous step-down switching regulator
- A5975AD Up to 2.5 A step down switching regulator for automotive applications
- ST1S03 1.5 A, 1.5 MHz adjustable, step-down switching regulator
- L4973 3.5 A step down switching regulator
- ST1S10 3 A, 900 kHz, monolithic synchronous step-down regulator IC
- L4971 1.5A Switching Regulator
- ST1S06 Synchronous rectification with inhibit, 1.5 A, 1.5 MHz fixed or adjustable, step-down switching regulator
- L4970A 10 A switching regulator
- L4963 1.5 A SWITCHING REGULATOR
- ST1S12XX Synchronous rectification with enable, 0.7 A, 1.7 MHz fixed or adjustable step-down switching regulator in TSOT23-5L
- A7986A 3 A step-down switching regulator for automotive applications
- A7985A 2 A step-down switching regulator for automotive applications
- L4972 2 A SWITCHING REGULATOR
- ST1S40 3 A DC step-down switching regulator
- L6926 High efficiency monolithic synchronous step-down regulator
- ST2S08B Dual synchronous rectification, 1.5 A, 1.5 MHz adjustable step-down switching regulator
- L4975A 5 A switching regulator
- L6981 38 V, 1.5 A synchronous step-down converter with low quiescent current
- L6983I 38 V 10W synchronous iso-buck converter for isolated applications
- L5986 2.5 A step-down switching regulator
- L5987 3 A step-down switching regulator
- L5970AD Up to 1 A step down switching regulator
- A6986 38 V, 2 A synchronous step-down switching regulator with 30 µA quiescent current
- A6985F Automotive 38 V, 500 mA synchronous step-down switching regulator with 30 µA quiescent current
- L6985F 38 V, 500 mA synchronous step-down switching regulator with 30 µA quiescent current
- L7987L 61 V 2 A asynchronous step-down switching regulator with adjustable current limitation
- PM8908 Monolithic buck converter for DDR memory termination
- ST1S32 4 A DC step-down switching regulator
- L6902 Up to 1 A switching regulator with adjustable current limit
- ST1S41 4 A step-down switching regulator
- ST2S06 Dual synchronous rectification with reset or inhibit, 0.5 A, 1.5 MHz adjustable step-down switching regulator
- L7985 2 A step-down switching regulator
- L7986TA 3 A step-down switching regulator
- L6982 38 V, 2 A synchronous step-down converter with low quiescent current
- L3751 Wide 6 V to 75 V input voltage synchronous buck controller
- L7986 3 A step-down switching regulator
- L6928 High efficiency monolithic synchronous step-down regulator
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